Octamethylene-bis(5-dimethylcarbamoxyisoquinolinium bromide) (4-673-745-01) is an extremely potent carbamate nerve agent.

It works by inhibiting acetylcholinesterase, causing acetylcholine to accumulate.

[1][2] Since the agent molecule is positively charged, it does not cross the blood brain barrier very well.

Sodium hydroxide is added to make the solution basic.

The solvent is evaporated and the solid residue is then recrystallized from petroleum ether.